A fiber optic communication system allows lightwave signals to be transmitted over long distances. The fiber optic communication system may include a transmitter that generates signals in the form of lightwave pulses, a receiver for receiving the lightwave pulses, and an optical fiber that connects the transmitter to the receiver. The lightwave pulses are generated by a laser that emits light having a band of wavelengths around a center wavelength. Because the speed of light through the fiber is a function of the wavelength (commonly referred to as chromatic dispersion), the components of a lightwave pulse having different wavelengths propagate through the fiber at slightly different speeds, resulting in a wider pulse at the receiver than was transmitted. The wider pulses may overlap, making it difficult to determine the boundaries of the pulses and causing errors in the detected signals.
In dense wavelength divisional multiplexing applications, several channels of signals are transmitted through the fiber at the same time. Each channel uses a band of wavelength with a different center wavelength. In order to accurately receive data, the receiver filters out the signals of a particular channel, and performs dispersion compensation to compensate for the chromatic dispersion effects. Dispersion compensation can also be applied prior to transmission. The signals are modified at the transmission end so that after traveling through the fiber, the signals become dispersion free at the receiving end.